Shock and Awe: The Story of Electricity -- Jim Al-Khalili BBC Horizon

at the dawn of the 19th century in a cellar in Mayfair the most famous scientist of the time Humphrey Davy built an extraordinary piece of electrical equipment four metres wide twice as long and containing stinking stacks of acid and metal it had been created to pump out more electricity than had ever been possible before it was in fact the biggest battery the world had ever seen and with it Davy was about to propel us into a new age [Music] [Applause] [Music] that moment would take place at a lecture at the Royal Institution in front of hundreds of London's great and good filled with anticipation they packed the seats hoping to witness a new and exciting electrical wonder but what they would see that night will be something truly unique something they'd remember for the rest of their lives using just two simple carbon rods Humphrey Davy was about to unleash the true potential of electricity [Music] electricity is one of nature's most awesome phenomena and the most powerful manifestation of it we ever see is lightning this is the story of how we first dreamed of controlling this primal force of nature and how we would ultimately become its master it's a 300 year tale of dazzling leaps of imagination and extraordinary experiments it's a story of maverick geniuses who used electricity to light our cities to communicate across the seas and through the air to create modern industry and to give us the digital revolution but in this film we'll tell the story of the very first scientists who started to unlock the mysteries of electricity is there something alive in there they studied it's curious link to life build strange and powerful instruments to create it and even tamed lightning itself it was these men who truly laid the foundations of the modern world and it all started with a spark imagine our world without electricity it will be darn cold and quiet in many ways it will be like the beginning of the 18th century where how story begins [Music] this is the Royal Society in London in the early 1700s after years in the wilderness Isaac Newton finally took control of it after the death of his arch enemy Robert Hooke Newton brought in his own people to the key jobs to help shore up his new position the new head of demonstrations there was 35 year old Frances Hawkes be notes from the Royal Society in 1705 reveal how hard Hawks be tried to stamp his personality on its weekly meetings producing ever more spectacular experiments to impress his masters in November he came up with this a rotating glass sphere he was able to remove the air from inside it using a new machine the air pump on his machine a handle allowed him to spin the sphere one by one the tangles in the room will put out and Francis placed his hand against the sphere the audience were about to see something amazing [Music] inside the glass sphere a strange ethereal light began to form dancing around his hand a light no one had ever seen before that's fantastic a suit beautiful blue glows is marking out the shape of my hands but then going like round the board there's something alive in there it's difficult to really understand why this dancing blue light meant so much but we have to bear in mind that at the time natural phenomena like this was seen to be the work of the Almighty this was still a period when even in Isaac Newton's theory God was constantly intervening in the conduct of the world and so it made sense for a lot of people to interpret natural phenomena as acts of God so when a mere mortal meddled with God's work it was almost beyond rational comprehension Hawks we never realized the full significance of his experiment he lost interest in his glowing sphere and spent the last few years of his life building ever more spectacular experiments for Isaac Newton to test his other theories he never realized that it unwittingly started an electrical revolution before Hawke's Bay electricity had been merely a curiosity the ancient Greeks rubbed amber which they called electron to get small shocks an even Queen Elizabeth the first marveled of static electricity power to lift feathers but now Hawkes bees machine could make electricity at the turn of a handle and you could see it and perhaps even more importantly his invention coincided with the birth of a new movement sweeping across Europe called the Enlightenment enlightened intellectuals used reason to question the world and their legacy was radical politics iconoclastic art and natural philosophy or science but ironically Hawkes B's new machine wasn't immediately embraced by most of these intellectuals but instead by conjurer's and street magicians and those with an interest in electricity called themselves electricians one story tells of a dinner party attended by an Austrian count the electrician had placed some feathers on the table and then charged up a glass rod with a silk handkerchief he then astonished the guests by lifting up the feathers with the rod he then went on to charge himself up using one of Hawkes B's electrical machines and gave the guests electric shocks presumably to squeals of delight but for his ps2 resistance he placed a glass of cognac in the center of the table charged himself up again and lit it with a spark from the tip of his finger there was a trick called the electrical beatification in which the victim sits on an insulated chair and above his head hangs a metal crown that doesn't quite touch his head and then if the crown is electrified then you get an electric discharge around the crown that looks exactly like a halo which is why it's called the electric beatification as England and the rest of Europe went electricity crazy the spectacles grew bigger and the more curious electricians started to ask more profound questions not only how can we make our shows bigger and better but how can we control this amazing power and for some can this incredible electrical fire do more than just entertain [Music] one of the first early breakthroughs would never have happened had it not been for a terrible accident this is Charterhouse in the center of London over the past 400 years it's been a charitable home for young orphans and elderly gentlemen and sometime in the 1720s it also became home to one Steven gray Steven gray had been a successful silk Dyer from Canterbury he was used to seeing electric sparks leap from the silk and they fascinated him unfortunately a crippling accident ended his career and left him destitute but then he was offered a new life here at Charterhouse and with it the time to perform his own electrical experiments here at Charterhouse possibly in this very room the great chamber Steven grade built a wooden frame from the top beam he suspended two swings using silk rope he also had a device like this a hawk's B machine for generating static electricity now with a large audience and attendance he got one of the orphan boys who lived here at Charterhouse to lie across the two swings gray placed some gold leaf in front of him [Music] he then generated electricity and charged the boy through a connecting rod [Music] gold leaf even feathers left to the boys fingers some of the audience claimed they could even see sparks flying out from his fingertips show business indeed [Music] but to the curious and inquiring mind of Stephen gray this said something else as well electricity could move from the machine to the boy's body through to his hands but the silk rope stopped it dead it meant the mysterious electrical fluid could flow through some things but not through others [Music] it led gray to divide the world into two different kinds of substances he called them insulators and conductors insulators held electric charge within them and wouldn't let it move like the silk or hair glass and resin whereas conductors allowed electricity to flow through them like the boy or metals it's a distinction which is still crucial even today just think of these electric pylons they work on the same principle that graded used nearly 300 years ago the wires are conductors the glass and ceramic objects between the wire and the metal of the pylon are insulators that stop the electricity leaking from the wires into the pylon and down to the earth they're just like the silk ropes in Gray's experiment back in the 1730's grey's experiment may have astounded all who saw it but it had a frustrating drawback try as he might grey couldn't contain the electricity he was generating for long it left from the machine to the boy and was quickly gone the next step in our story came when we learnt how to store electricity but that would take place not in Britain but across the channel in mainland Europe [Music] across the channel electricians were just as busy as their British counterparts and one Center for electrical research was here in Leiden Holland [Music] and it was here that a professor came up with an invention that many still regard as the most significant of the 18th century one that in some form or another can still be found in almost every electrical device today that professor was Pieter van mushin Brooke unlike Hawkes being gray mission Brooke was born into academia but ironically enough his breakthrough came not because of his rigorous science but because of a simple human mistake he was trying to find a way to store electrical charge ready for his demonstrations and you can almost hear his train of thought as he tries to figure this out if electricity is a fluid that flows a bit like water then maybe you can store it in the same way that you can store water so mission Brooke went to his laboratory to try to make a device to store electricity motion Brooke started to think literally he took a glass jar and poured in some water he then placed inside it a length of conducting wire which was connected at the top to a hawk speed electric machine then he put the jar on an insulator to help keep the charge in the jar he then tried to pour the electricity into the jar produced by the machine via the wire down through into the water but whatever he tried the charge just wouldn't stay in the jar then one day by accident he forgot to put the jar on the insulator but charges instead while it was still in his hand [Music] finally holding the jar with one hand he touched the top with the other and received such a powerful electric shock he was almost thrown to the ground he writes it's a new but terrible experiments which I advise you never to try nor would I who've experienced it and survived by the grace of God do it again for all the kingdom of France so I'm going to heed his advice not touch the top but instead see if I can get a spark off of it the sheer power of the electricity which flew from the jar was greater than any seen before and even more surprisingly the jar could store that electricity for hours even days so in honor of the city where motion Brooke made his discovery they called it the Leyden jar and it's Fame swept across the world and very rapidly from 1745 through the rest of the 1740s the news of this it's called the Leyden jar goes global it spreads from Japan in East Asia to Philadelphia in eastern America it became one of the first quick globalized scientific news items but although the Leyden jar became a global electrical phenomenon no one had the slightest idea how it worked you have a jar of electric fluid and it turns out that you get a bigger shock from the jar if you allow the electric fluid to drain away to the earth why is the shock bigger if the jars leaking why isn't the shock bigger if you make sure that all the electric fluid stays inside the jar that was how mid 18th century electrical philosophers were faced with this challenge [Music] electricity was without doubt a fantastical wonder it could shock and spark it could now be stored and moved around yet what electricity was how it worked and why did all these things was nothing less than a complete mystery [Music] within ten years a new breakthrough was to come from an unexpected quarter from a man politically and philosophically at war with the London establishment and even more shockingly for the British electrical elite that man was merely a colonial an American this painting of Benjamin Franklin hangs here at the Royal Society in London Franklin was a passionate supporter of American emancipation and saw the pursuit of rational science and particularly electricity as a way of rolling back ignorant false idols and ultimately his intellectually elitist colonial masters and this is mixed with a profoundly egalitarian Democratic idea that Franklin and his allies have which is this is a phenomenon open to everyone here's something that the elite doesn't really understand and we might be able to understand it here's something that the elite can't really control but we might be able to control and here's something above all which is the source of superstition and we rational egalitarian potentially democratic intellectuals we will be able to reason it out without appearing to be the slaves of magic or mystery so Franklin decided to use the power of reason to rationally explain what many considered a magical phenomenon lightning this is probably one of the most famous scientific images of the 18th century it shows Benjamin Franklin the heroic scientist flying a kite in a storm proving that lightning is electrical but although Franklin proposed this experiment he almost certainly never performed it much more likely is that his most significant experiment was another one which he proposed but didn't even conduct in fact it didn't even happen in America it took place here in a small village north of Paris called Mali level the French adored Franklin especially his anti British politics and they took it upon themselves to perform his other lightning experiments without him I've come to the very spot where that experiment took place [Music] in May 1750 to George Louis LeClair known across France as the Comte de Buffon and his friend Thomas Francois de Labarre erected a 40-foot metal pole more than twice as high as this one held in place by three wooden staves just outside deli bars house here in Mali level the metal pole rested at the bottom inside an empty wine bottle Franklin's big idea had been that the long pole would capture the lightning pass it down the metal rod and store it in the wine bottle at the base which worked as a Leyden jar then he could confirm what lightning actually was all his French followers had to do was wait for a storm and then on May 23rd the heavens opened at 12:20 a loud thunderclap was heard as lightning hit the top of the pole an assistant ran to the bottle a spark left a cross between the metal and his finger with a loud crack and a sulfurous smell burning his hand the spark revealed lightning for what it really was it was the same as the electricity made by man it's hard to overestimate the significance of this moment Nature had been mastered not only that but the wrath of God itself had been brought under the control of mankind it was a kind of heresy Franklin's experiment was very important because it showed that lightning storms produce or are produced by electricity and that you can bring this electricity down electricity is a force of nature that's waiting out there to be tapped next Franklin turned his rational mind to another question why the Leyden jar made the biggest sparks when it was held in the hand why didn't all the electricity just drain away and drawing on his experience as a successful businessman he saw something no one else had that liked money in a bank electricity can be in credit what he called positive or debit negative for him the problem of the Leyden jar is a problem of Accountancy Franklin's idea was every body has around it an electrical atmosphere and there's a natural amount of electric fluid around each body if there's too much we'll call it positive if there's too little we'll call it negative and nature is organized so the positives and the negatives always want to balance out like an ideal American economy Quinn's insight was that electricity was actually just positive charge flowing to cancel out negative charge and he believed this simple idea could solve the mystery of the Leyden jar as the jar is charged up negative electrical charge is poured down the wire and into the water if the jar rests on an insulator a small amount builds up in the water but if instead the jar is held by someone as it's being charged positive electric charge is sucked up through their body from the ground to the outside of the jar trying to cancel out the negative charge inside but the positive and negative charges are stopped from cancelling out by the glass which acts as an insulator so instead the charge just grows and grows on both sides of the glass then touching the top of the jar with the other hand completes a circuit allowing the negative charge on the inside to pass through the hand to the positive on the outside finally canceling it out the movement of this charge causes a massive shock and often a spark the modern equivalents of the Leyden jar is this the capacitor and it's one of the most ubiquitous of electronic components is found everywhere there are a number of smaller ones scattered around on this circuit board from a computer they help smooth out electrical surges protecting sensitive components even in the most modern electric circuit solving the mystery of the Leyden jar and recognizing lightning as merely a kind of electricity with two great successes for Franklin and the new enlightenment movement [Music] but the forces of trade and commerce which helped fuel the Enlightenment were about to throw up a new and even more perplexing electrical mystery a completely new kind of electricity this is the English Channel by the 17th and 18th centuries a good fraction of the world's wealth flowed up this stretch of water from all corners of the British Empire and beyond on its way to London spices from India sugar from the Caribbean wheat from America tea from China but of course it wasn't just commerce new plants and animal specimens from all over the world came flooding into London including one that particularly fascinated the electrician's called the torpedo fish it been the stuff of fishermen's tales its sting it was said was capable of knocking a grown man down but as the electricians started to investigate the sting they realized it felt strangely similar to a shock from a Leyden jar could it sting actually be an electric shock but first many people dismiss the torpedo fish as shocked as a cult some said it was probably just the fish biting others that it couldn't be a shock because without a spark it just wasn't electricity but for most this was a very strange and inexplicable new mystery and it would take one of the oddest yet most brilliant characters in British science to begin to unlock the secrets of the torpedo fish this is the only picture in existence of the pathologically shy but exceptional Henry Cavendish this one only exists because an artist sketched his coat as it hung on a peg then filled in the face from memory his family were fantastically rich they were the Devonshire's who still owned Chatsworth House in Derbyshire but Henry Cavendish decided to turn his back on his family's wealth and status to live in London near his beloved Royal Society where he could quietly pursue his passion for experimental science when he heard about the electric torpedo fish he was intrigued a friend wrote to him on this my first experience of the effects of the torpedo I exclaimed that this is certainly electricity but how and to work out how a living thing could produce electricity he decided to make his own artificial fish these are his plans to Leyden jars shaped like the fish which were buried under sand when the sand was touched they discharged giving a nasty shock his model helped convince him that the real torpedo fish was electric but it still left him with a nagging problem although both the real fish and Cavendish's artificial one gave powerful electric shocks the real fish never sparked Cavendish was perplexed how could it be the same kind of electricity if they didn't both do the same kinds of things Cavendish spent the winter of 1773 in his laboratory trying to come up with an answer and in the spring he had a brainwave Cavendish's ingenious answer was to point out a subtle distinction between the amount of electricity and its intensity the real fish produced the same color of electricity is just that it was less intense now for a physicist like me this marks a crucial turning point because it's the moment when two genuinely innovative scientific ideas first crop up what Cavendish refers to as the amount of electricity we now call electric charge and his intensity is what we call the potential difference of voltage so the Leyden jars shock was high voltage but low charge whereas the fish was low voltage and high charge and it's possible to actually measure that hiding at the bottom of this tank under the sand is the torpedo Mar Murata and it's an electric ray you can just see his eyes protruding from the sand this is a fully grown female and I'm going to try and measure the electricity it gives off with this bait I've got this fish connected to a metal rod and hooked up to an oscilloscope to see if I can measure the voltage as it catches its prey so here goes oh there's one [Music] and there's another one the fish gave a shock of about 240 volts the same as mains electricity but still roughly ten times less than the Leyden jar well that would have given me quite a nasty shock and I can only to try and imagine what it must have been like for scientists in the 18th century to witness this an animal a fish producing its own electricity Cavendish had shown that the torpedo fish made electricity but he didn't know if it was the same kind of electricity as that made from an electrical machine is the electrical shock that a torpedo producers is it the same as produced by an electrical machine or are there two kinds as a kind that's generated artificially or is there a kind of animal electricity that only exists in living bodies as is a huge debate that divided opinion for several decades and out of that bitter debate came a new discovery the discovery that electricity needn't be a brief shot or spark but could actually be continuous and the generation of continuous electricity would ultimately propel us into our modern age [Music] but the next step in the story of electricity would come about because of a fierce personal and professional rivalry between two Italian academics [Music] this is Bologna University one of the oldest in Europe in the late 18th century the city of Bologna was ruled from papal Rome which meant that the university was powerful but conservative in its thinking it was steeped in traditional Christianity one where God ruled earth from heaven but that the way he ran the world was hidden from us mere mortals we were not meant to understand him only to serve him and one of the university's brightest stars was the anatomist Luigi Eliseo Galvani but in a neighboring city a rival electrician was about to take Galvani to task this is jávea only a hundred fifty miles from bologna but by the end of the 18th century worlds apart politically it was part of the Austrian Empire which put it at the very heart of the European enlightenment liberal in its thinking politically radical and obsessed with the new science of electricity it was also home to Alessandro Volta Alessandro Volta couldn't have been more unlike Galvani from an old Lombardi family he was young arrogant charismatic a real ladies man and he courted controversy unlike Galvani he'd like to show off his experiments on an international stage to any audience vaulters ideas were unfettered by Galvani's religious dogma like Benjamin Franklin and the European enlightenment he believed in rationality the scientific truth like a Greek God would cast ignorant to the floor superstition was the enemy reason was the future [Music] both men were fascinated by electricity and both brought their different ways of seeing the world to bear on it Galvani had been attracted to the use of electricity in medical treatments for instance in 1759 here in Bologna electricity was used on the muscles of a paralyzed man one report said it was a fine sight to see the mastoid rotate the head the biceps bend the elbow in short to see the force and vitality of all the motions occurring in every paralyzed muscle subjected to the stimulus Galvani believed these kinds of examples revealed that the body worked using animal electricity a fluid that flows from the brain through the nerves into the muscles where it's turned into motion and who devised a series of grisly experiments to prove it now he first prepared a frog he writes the Frog is skinned and disemboweled only their lower limbs are left join together containing just the cruel nerves well I've left my frog mostly intact but I've exposed the nerves that connect to the frog's legs then he used hawks bees electrical machine to generate the electrostatic charge that would accumulate and travel along this arm and out through this copper wire then he connected the charge carrying wire to the Frog and another to the nerve just above the neck let's see what happens oh and the frog's leg twitches just as he makes contact there we go now for Galvani what was going on there was that there's a strange special kind of entity in them in the animal muscle which he calls animal electricity it's not like any other electricity its intrinsic to living beings but for Volta animal electricity smacked of superstition and magic it had no place in rational and enlightened science Volta saw the experiment completely differently to Galvani he believed it reveals something totally new for him the legs were jumping as a result of the release of animal electricity from within them but because of the artificial electricity from outside the legs were merely the indicator they were only twitching because of the electricity from the horse be machine back in Bologna Galvani reacted furiously to vaulters ideas he believed Volta had crossed a fundamental line from electrical experiment into God's realm and that was tantamount to heresy to have a kind of spirit like electricity to have that produced artificially and to say that that spirit that living force that agency was the same that something produced by God that God had put into a living human body or a frog's body that seemed sacrilegious to them because it was eliminating this boundary between God's realm of the divine and the mundane realm of the material spurred on by his religious indignation Galvani announced a new series of experimental results which would prove that Volta was wrong during one of his experiments he hung his frogs on an iron wire and saw something totally unexpected if he connected a copper wire to the wire the frog was hanging from and then touched the other end of the copper to the nerve it seemed to him that he could make the frog's leg twitch without any electricity at all Cavani came to the conclusion that it must have been something inside the frog's even if dead that continued for a while after death to produce some kind of electricity and the metal wires was somehow releasing that electricity over the next month's Galvani's experiments focused on isolating this animal electricity using combinations of frog and metal Leyden jars and electrical machines for Galvani these experiments were proof that the electricity was originating within the frog itself the frogs muscles were Leyden jars storing up the electrical fluid and then releasing it in a burst on the 30th of October 1786 he published his findings in a book de animali electricity of animal electricity Galvani was so confident of his ideas he even sent a copy of his book to Volta but Volta just couldn't stomach Galvani's idea of animal electricity he thought the electricity just had to come from somewhere else but where in the 1790s here at the University of Pavia almost certainly in this lecture theater which still bears his name voltar began his search for the new source of electricity his suspicions focused on the metals that Galvani had used to make his frog's legs twitch his curiosity had been piqued by an odd phenomenon that he'd come across how combinations of metals tasted he found that if he took two different metal coins and placed them on the tip of his tongue and then placed a silver spoon on top of both he got a kind of tingling sensation rather like the tingling you'd get from the discharge of a Leyden jar Volta concluded that he could taste electricity and that it must be coming from the contact between the different metals in the coins and spoon his theory flew in the face of Galvani's the frog's leg switched not because of its own animal electricity but because it was reacting for the electricity from the metals but the electricity his coins generated was incredibly weak how could he make it stronger [Music] then an idea came to him as he revisited the scientific papers from the great British scientist Henry Cavendish and in particular his famous work on the electric torpedo fish he went back and took a closer look at the torpedo fish and in particular the repeating pattern of chambers in its back he wondered whether it was this repeating pattern that held the key to its powerful electric shock perhaps each chamber was like his coins and spoon each generating a tiny amount of electricity and perhaps the fish's powerful shock results from the pattern of chambers repeating over and over again with growing confidence in his new ideas Volta decided to fight back by building his own artificial version of the torpedo fish so he copied the torpedo fish by repeating its pattern but using metal here's what he did he took a copper metal plate and then placed above it a piece of card soaked in dilute acid then above that he took another metal and placed it on top while he had here was exactly the same thing as Galvani's two wires but now Volta repeated the process what he was doing here was building a pile of metal in fact his invention became known as the pile but it's what it could do that was the really incredible revelation Volta then tried his pile out on himself by getting two wires and attaching them to each end of the pile and bringing the other ends to touch his tongue he could actually taste the electricity this time it was more powerful than normal and it was constant he'd created the first battery the machine was no longer an electrical and mechanical machine it was just a purely electrical machine so he proved that a machine imitating the fish could work that what he calls the metal or contact the electricity of different methods could work and that he regarded as his final winning move in the controversy with Galvani what vaulters piles showed was that you could develop all the phenomena of animal electricity without any animals being present so from the voltaic point of view it seemed as if Galvani was wrong there's nothing special about the electricity in animals it's electricity and it can be completely mimicked by this artificial pile but the biggest surprise for Volta was that the electricity it generated was continuous in fact it poured out like water in a stream and just as in a stream where the measure of the amount of water flowing is called a current so the electricity flowing out of the pile became known as an electrical current [Music] 200 years after Volta we finally understand what electricity actually is the atoms in metals like all atoms have electrically charged electrons surrounding a nucleus but in metals the atoms share their outer electrons with each other in a unique way which means they can move from one atom to the next [Music] if those electrons move in the same direction at the same time the cumulative effect is a movement of electric charge this flow of electrons is what we call an electric current within weeks of bolts of publishing details of his pile scientists were discovering something incredible about what it could do its effect on ordinary water was completely unexpected the constant stream of electric charge into the water was ripping it up into its constituent parts the gases oxygen and hydrogen electricity was heralding the dawn of a new age a new age where electricity ceased being a mere curiosity and started being genuinely useful with constant flowing current electricity new chemical elements could be isolated with ease and this laid the foundations for chemistry physics and modern industry vaulters pile changed everything [Music] the panel made Volta and international celebrity fate sit by the powerful and the rich in recognition a fundamental measure of electricity was named in his honor the vault but his scientific adversary didn't fare quite so well Luigi Eliseo Galvani died on the 4th of December 1798 depressed and in poverty for me though it's not the invention of the battery that marks the crucial turning point in the story of electricity it's what happened next [Music] it took place in London's Royal Institution it was a moment that marked the end of one era and the beginning of another [Music] it was overseen by Humphrey Davy the first of a new generation of electricians young confident and fascinated by the possibilities of continuous electrical current so in 1808 he built the world's largest battery it filled an entire room underneath the Royal Institution it had over 800 individual voltaic piles attached together it must have hissed and breathed sulfurous fumes in a darkened room lit by centuries-old technology candles and oil lamps davy connected his battery to two carbon filaments and brought the tips together the continuous flow of electricity from the battery through the filaments left across the gap giving rise to a constant and blindingly bright spark [Music] outs of the darkness came the lights [Applause] Davy's arclights truly symbolizes the end of one era and the beginning of our era the era of electricity [Music] but there are truly grisly coda to this story in 1803 Galvani's nephew won Giovanni aldini came to London with a terrifying new experiment a convicted murderer called George Forster had just been hanged in new gates and when the body was cut down from the gallows it was brought directly to the lecture theatre where eldini started his macabre work using a voltaic pile he began to apply an electric current to the dead man's body then eldini put one electrical conductor in the dead man's anus and the other at the top of his spine Foresters limp dead body Sat bolt upright and his spine arched and twisted for a moment it seemed as though the dead body had been brought back to life it appears as though electricity might have the power of Resurrection and this made a profound impact on a young writer called Mary Shelley Mary Shelley wrote one of the most powerful and enduring stories ever based partly here on Lake Como Frankenstein tells the story of a scientist a Galvin is probably based on eldini who brings a monster to life using electricity and then disgusted by his own arrogance he abandons his creation just like Davey's arc lamp this book symbolizes changing times the end of the era of miracles and romance and the beginning of the era of rationality industry and science and it's that new age we explore in the next program because at the start of the 19th century scientists realized that electricity was intimately connected with another of nature's mysterious forces magnetism and that realization would completely transform our world electricity is one of nature's greatest forces and by the middle of the 20th century we'd harnessed its two lights and power our modern world hundreds of years of scientific discoveries and inventions brought us here but it would take the eccentric genius of one man to unlock the full potential of electrical power in the winter of 1943 nikola tesla looked towns across the manhattan skyline for the very last time Tesla had been born into a world powered by steam and lit by gas but before his eyes he saw a new world a world transformed a world powered by electricity his world frail lonely and still mourning the death of one of his beloved pigeons this extraordinary and eccentric genius knew that his life's work was done and he lay back on his bed to die you'll be three days before anyone found his body just over 200 years ago early scientists discovered electricity could be much more than simply a static charge it could be made to flow in a continuous current [Music] but they were about to discover something profound that electricity is connected to magnetism harnessing the link between magnetism and electricity would completely transform the world and allow us to generate seemingly limitless amounts of electrical power [Music] this is the story of how scientists and engineers unlocked the nature of electricity and then used it in an extraordinary century of innovation and invention but not before one of the most shocking engineering rivalries in history was finally laid to rest our story begins in London at the beginning of the 19th century with a young man who would further our understanding of electricity as much as any other on the 29th of February 1812 a 20 year old self educated book binder called Michael Faraday came here to the Royal Institution of Great Britain he was surrounded by the great and the good of the academic world and he was about to listen to one of the greatest scientific minds of the age Faraday the son of a blacksmith had finished his formal education when he was just 12 years old he would never get to university but he wasn't finished with learning as he was fascinated by science Faraday worked long and hard during the day burning books but in the evenings he would read whatever scientific literature he could lay his hands on he loved learning new things about the world and he had this constant desire this passion to understand why things were the way they were reading scientific papers was one thing but to really satisfy his craving for knowledge Faraday was desperate to see the experiments themselves and he eventually got his chance when he was given a ticket to attend one of the last lectures of England's greatest chemists at the time sir Humphrey Davy it was to change young Faraday's life forever after watching Devi or inspired and full of ideas Faraday knew what he wanted to do with his life he was determined to dedicate himself to furthering science and that's just what he did within a year Devi had appointed him as an assistant at the Royal Institution with Devi as his patron and well his boss faraday studied all manner of chemistry but what would inspire his greatest breakthroughs with the invisible forces of electricity and magnetism in 1820 both were being studied by a Danish scientist Hans Christian Oersted who'd made an extraordinary discovery he passed electric current through a copper rod and brought it close to a magnetic compass needle and saw that it made the needle rotate to earth stead it was remarkable he'd shown for the first time then electric currents can create a magnetic force he'd bound electricity and magnetism together today we call it electromagnetism and it's one of the fundamental forces of nature versus discovery sparked off a whole new Specht of inventive activity around and about the fields of electricity you can almost see electrical experimenters vying competing with each other to find new links between electricity and the other powers of nature at the Royal Institution Faraday set about recreating Earth's Ted's work which would mark his first steps to fame and fortune and through his rigorous research he concluded that there must be a flow of forces acting between the wire and the compass needle the device he designed to demonstrate it would change the course of history Faraday created a circuit using a battery like this a pair of wires and a mercury bath now the circuit carries on through these copper posts and this wire hangs freely it dangles into the mercury now because mercury is such a good conductor it completes the circuit when the current runs through the circuit it generates a circular magnetic force field around the wire now this interacts with the magnetism from a permanent magnet that Faraday had placed in the middle of the mercury together they forced the wire to move Faraday had proved that this invisible force really does exist and he could see its effect circular motion this beautiful device was the first to convert electric current into continuous motion basically it's the earliest ever electric motor the Faraday was about to take this experiment further one the lasting effects of Faraday's discovery of a little irritations in 1821 was that it showed that there was a relationship of some sort between electricity magnetism and motion Faraday explored this relationship in detail and set himself an even more difficult challenge to use magnetism and motion to make electricity eventually his obsession hard work and determination paid off the breakthrough came on the 17th of October 1831 when Faraday took a magnet like this and moved it in and out of a coil of wire he was able to detect a tiny electric current in the coil moving one way and then the other Faraday knew he was onto something a few days later instead of moving the magnet through the conducting wire coil he set up the equivalent experiment by moving a conducting copper plate through the magnetic field he didn't know it at the time but as his spinning disk cut through this magnetic field billions of negatively charged electrons were deflected from their original circular course and began to drift towards the edge a negative charge built up at the outer edge of the disk leaving a positive charge at the center and once the disk was connected to wires the electrons flowed in a steady stream Faraday had generated a continuous flow of electric current unlike a battery his current flowed for as long as his copper disc was spun he'd created electrical power directly from mechanical power though Faraday's discovery of induction was extraordinarily important in its own right and had profound effects for the understanding of electricity and technology for the rest of the 19th century but Faraday what it did was open a decade of powerful research because it gave him the clue about how he should pursue his was Cerf while Faraday continued his work trying to understand the very nature of electricity inventors from across Europe were less interested in the science and more interested in how electricity could make their money what's actually quite remarkable is certainly from a contemporary perspective is that by and large nobody really seems to care very much what electricity is you don't have great theoretical debates as to whether as a force of fluid on a principle or a power what they're really interested in is what electricity can do Faraday living in a world of steam power was informing the scientific community about the nature of electricity but at the same time another breakthrough in how we could actually use it have been made this will be the first device that really brought electricity out of the laboratory and into the hands of ordinary people the Telegraph the key to understanding the Telegraph is understanding a special kind of magnets and electromagnets basically a magnet created by an electric current the first electromagnets were developed independently by William sturgeon in Britain and Joseph Henry in America and just as Faraday had discovered that by coiling his wire he could increase the current in it produced by the moving magnets so Henry and sturgeon discovered that by adding more coils in their currents carrying wires they could make a more concentrated magnetic field basically the more coils the more turns the stronger the magnet so if I pass a current through this electromagnet you can actually see the effects of the magnetic field this is the standard school experiments of sprinkling iron filings on top of the magnet I give it a tap see the iron filings follow the contours of the field this allows us to visualize the effects of magnetism to make an electromagnet even stronger Henry and sturgeon discovered that they could place certain kinds of metal inside the electromagnetic coil the reason iron is so effective is fascinating because you can think of it as being made up of lots of tiny magnets all pointing in random directions at the moment this is not a magnet the tiny magnets inside are aligned similarly to these compass needles if you see they're all pointing in different directions but when you apply a magnetic field they all align together they all combine these magnets and cumulatively they add to the strength of the electromagnet so what Henry and sturgeon did was place two electromagnetic coils on each arm of their horseshoe to create something it was many many times more power and we can see the power of this horseshoe electromagnet if I turn it on and use something slightly bigger than iron filings these small pieces of iron the strength of the magnetic field holding them in place what's important to remember of course is that this electromagnet only works all the time there's a current passing through it as soon as I turn off the current the magnetism disappears early experimenters showed off this power by lifting metal weights Henry even made one big enough to lift a ton and a half of metal impressive but not world-changing but place that magnet much further away at the end of a wire and suddenly you can make something happen at your command in an instant this ability to control a magnet at a distance is one of the most useful things we've ever discovered if electricity can be made visible a long way away from the original source of power then you've got a source of instantaneous communication by the middle of the 1840s Samuel Morse had developed a messaging system based on how long an electrical circuit was switched on or off a long pulse of currents for a - a short burst for a dot this allowed messages to be sent and received by using a simple code contemporary early Victorian commentators reflect on the fact that electricity on a telegraph is literally making their world a smaller place you very often get a sort of rhetoric throughout the 19th century when people are talking about the telegraph about how more communication more understanding will render war obsolete because we all understand each other better I mean retrospectively it seems hopelessly utopian by the 1850s Europe and America were criss crossed with land-based telegraph wires but the dream of instant global communication was frustratingly out of reach this was because there was still no cable capable of carrying messages between two of the greatest powers on earth Britain and America many experts were convinced that a working Atlantic cable was impossible but those who disagreed knew that if they could solve this problem it could make them serious money and in the 1850s American businessman and British engineers joined forces to prove this could be done attempt after attempts ended in disaster the heavy cables kept snapping in heavy seas and storms finally on the 29th of July 1858 two parts of a cable were spliced together in mid-atlantic you see a single cable was simply too big to have been carried by one ship then one end was taken to Newfoundland and the other end to Southwest Ireland six days later the first direct link between the two most powerful nations in the world was in place the project was hailed a huge success and a formal message of congratulations was sent from Queen Victoria to President Buchanan but before the celebrations were over things started to go very wrong this is chief engineer brights original notebook you can see here Queen Victoria's original message now it's only 98 words long but it took 16 hours to transmit the telegraph operators on the other side found it very hard to decipher the message the electrical signals that they were receiving were blurred and distorted and they kept asking for words to be repeated over and over again so you can see here repeat after sending waiting to receive no signals clearly transmitting across the Atlantic wasn't going to be as straightforward as people had hoped over the next few days several hundred messages were exchanged but those arriving in Newfoundland became almost impossible to decipher just a jumbled mess of dots and dashes there was a serious problem with the cable and it was getting worse while the 1858 cable was never fully repaired and the end finally came when British engineer Wildmon Whitehouse mistakenly believed that by increasing the signal voltage he could force the messages through to Newfoundland the cable simply stopped working altogether [Music] at the time increasing the voltage by using more powerful batteries made sense most experts believed electric current flowed through a cable like a fluid in a pipe increasing the voltage was the equivalent of increasing the pressure in the system forcing the current through to the other end but the Telegraph was actually carrying pulses or ripples of currents along the cable not a continuous stream and over long distances these pulses were becoming distorted making it difficult to tell what was a short dot and which was a longer - by studying the effectiveness of underwater cabling scientists were beginning to understand that electric current didn't always flow like water but was also creating invisible electromagnetic waves or ripples and it's this breakthrough that would lead to a new branch of research into the electromagnetic spectrum and solve the problems of the Atlantic Telegraph in effect the transatlantic cable was a giant ambitious hugely expensive experiment the failure of science to keep pace with technology have been exposed and a new more theoretical and for me much more exciting approach to understanding electricity began to unfold armed with this new understanding of how electric pulses actually moved along the cable improvements were made to its composition design and how it was laid it would take another eight years of scientists and engineers working together before a working cable was finally put in place and on Friday the 27th of July 1866 a message was sent from Ireland to Newfoundland clear and crisp the Treaty of peace has been signed between Austria and Prussia at last the dream of instant transatlantic communication had become a reality the success of the 1866 cable makes the world a smaller place yet again a change for the world in where it took days or weeks or months for information to travel to a world in which information two seconds or minutes to travel now is far more profound I think than anything that's taken place to in my lifetime the invention of the Telegraph changed ordinary people's lives but it will be the breakthroughs in how we used continuously flowing electric currents they would have an even greater impact because inventors were developing a new way of using electricity to make something every person in the world would want electric light until the 19th century we only knew of one way to make our own light burn things and by the middle of the 19th century we've perfected a very effective way of lighting our homes using gas [Music] a typical British home in the 1860s would have been lit like this highly flammable gas would have been pumped directly into people's houses through a network of pipes but these gas lamps were too dull for large outdoor areas so railway stations and streets began to be lit from a more powerful source electric arc lights the first arc lights were demonstrated by Michael Faraday's mentor Sir Humphrey Davy at the Royal Institution as early as 1808 and they worked by passing a continuous spark of electricity across two carbon rods but their intense white glow was just too bright for people's homes for an electric light to compete with gas it would need to be subdivided into many smaller less powerful and more gentle lamps whoever succeeded in bringing electric lights to every home in the land was guaranteed fame and fortune and by the early 1880s the most famous most prodigious most fiercely competitive inventor in the world had taken on the challenge the American Thomas Alva Edison Bert Edison invention was a passion it's what he loved doing he loved being in the laboratory the first thing that drove that passion is that it was a lot of fun for Edison I think that was the thing that he found most exciting is that this was something he did well and it allowed all of his creativity to come to the floor Edison is mr. electrical invention he's the man they trust he's the man that they think can do anything he's also the man who has his carefully cultivated connections with entrepreneurs where people are willing to put you put their cash where Edison's mouth is so to speak and back in in the sort of venture for Edison the money was probably the least important reason for Edison the money was important for one reason to allow him to do the next project Edison had assembled a group of young and talented engineers at a cutting-edge laboratory in New Jersey 26 miles from Manhattan Menlo Park would become the world's first research and development facility allowing Edison's team to invent on an industrial scale they worked incredible hours you know one of them talked about how he ever hardly ever saw his children because he was in the lab all the time [Music] but they knew they were in the midst of something really important right that if Edison succeeded right if they succeeded with Edison that their futures were secure [Music] Edison's dream was to bring electric lights to every home in the land and with his team of engineers behind him and the vision of an electric future ahead he launched his campaign the race to bring electric light to the world was to play out in the great cities of the time New York Paris London Edison's Menlo Park team set about developing a totally different form of electric lamp the incandescent light bulb in fact Edison's light bulb design wasn't all that new or unique French Russian Belgian and British inventors have been perfecting similar bulbs for over 40 years and one of them an Englishman Joseph Swan had been developing his own version of an incandescent lamp both Swan and Edison's light bulbs work by passing an electric current through a filament now a filament is a material in which the electric current flows through with more difficulty than it does through the copper wire in the rest of the circuit and it relies on the idea of resistance now inside this jar I have a filament made out of ordinary pencil lit and we can see what happens as I pass a current through it down at the atomic scale the atoms in the filament impede the flow of electricity so it takes more energy to force it through and this energy is deposited in the filament as heat now as it heats up it's resistance goes up which again raises its temperature until it glows white hot now one of the first materials Edison used for his filaments was platinum with its relatively high melting point platinum could be heated to a white-hot temperature without melting it could also be stretched into thin strands and the thinner the Strand the more resistance it offered to the current passing through it but platinum was expensive and didn't offer enough resistance the race was on to find a better alternative and the solution came when the Menlo Park team switched to a method Swan was also developing using a vacuum to stop Cheaper carbon filaments from burning up too quickly Edison and Swan tested all kinds of different materials for their filaments everything from raw silk and parchments to cork edison even tested his engineers beard hair eventually he settled on bamboo fiber while Swan used a treated cotton thread Edison and swans light bulb designs were very similar eventually they came to an agreement and went into partnership to sell light bulbs in the UK today many people still believe that Edison alone invented the light bulb while Swan has become a footnote in history but his incandescent bulb was only part of Edison's strategy he'd also invented an entire electrical system of sockets cables and meters to go with it and being a brilliant businessman he developed a groundbreaking new way of distributing electricity Edison knew that the key to making money from his system was to generate the electricity in a Central Station and then sell it to as many customers as possible it seems obvious to us now but until then anyone who wanted to use electricity had to have their own noisy generator to make it Edison's ambition was huge he wanted to light the fastest-growing and most exciting city in the world New York in the summer of 1882 Edison stood in a unique position at the center of 19th century science and invention he'd patented a cutting-edge incandescent light bulb he'd amassed an unprecedented knowledge of electrical engineering and above all he'd cultivated a reputation among the American public of being such a genius inventor that journalists hung on his every word and the financial muscle of Wall Street was quick to throw itself behind his new ideas his vision to electrify Manhattan and then of course the rest of the world was seemingly within his grasp because Edison and his team were about to launch their most expensive and risky project yet America's first power station generating continuous direct current just before 3 p.m. on the 4th of September 1880 - Thomas Edison surrounded by a gaggle of bankers dignitaries and reporters entered JP Morgan's building right behind me flicked one of the Edison patented switches and 100 of his incandescent bulbs began to glow turning to a nearby journalist he said I have accomplished all that I promised half a mile away on Pearl Street Edison's new power station costing half a million dollars and four years of hard work had sprung into life the currents surged through buried cables stretching out in each direction of course it might seem obvious to us now but in New York back in the early 1880s the idea of burying electric cables underground seemed like an unnecessary expense this street would have been criss crossed with hundreds of cables used for Telegraph's telephones and arc street lighting looking up you'd have seen a tangled mass of black spaghetti blocking out the light Edison knew this dangerous situation had to change and for him to make as much money as he could electricity needed rebranding it had to be considered safe so Edison is arguing both for the greater safety of his DC low voltage system and 400 round lines he can argue that he has a much safer system than electric arc light for streets or gas lighting for indoor lighting he doesn't have to worry about fires doesn't have to worry about electrocution that all of this is much safer because of the system he's created with this underground system burying every cable was not only very expensive but was a logistical nightmare because this was one of the busiest square miles in the world Edinson chose this area for a reason Wall Street's rich important influential because for Edison's system to make money all these wealthy customers had to be within a mile of his power station and this was because Edison calculated the thickest cable he could afford would only carry an adequate amount of his continuous direct current to customers within this range this was a huge leap forward because for the first time dozens of customers could be supplied by just one power station but there was a big problem Edison's Network could never be economical in lighting America's new suburbs they just didn't have the concentration of customers needed to make building these expensive power stations worthwhile how do we stuck with Edison's way of generating and distributing electricity the world would be a very different place we'd have to have power stations scattered around no more than a mile apart even in the centers of our towns or cities and it will be extraordinary expensive to even provide power for smaller communities but someone who held the answers to these problems was about to enter the story someone who would help create the modern world and who'd play an integral part in one of the biggest fallouts in scientific history his name was Nikola Tesla and he was right under Edison's nose Nikola Tesla was a Serbian inventor who was born in Croatia and who worked for Edison briefly after arriving in New York at the age of 28 European introverted a deep thinker he was everything Edison wasn't Edison and Tesla could not be more different in the way that they handled herself appearance and their and their manners and the way that they constructed a public image for themselves Edison could care less about the clothes that he had on and if he spilled chemicals on his good Sunday suit then he spilled chemicals on his good Sunday suit he he was you know basically the very various kind of slob 'only guy Tesla on the other hand even as a young man in his mid-20s is thinking about his appearance how he comes across the people she cares about his clothes he cares about his manner indeed he even cares about how is how his photograph his portraits are taken and he always wants to make sure that he has a nice three-quarter profile so you don't see that the fact that he has a bit of a pointy chin the life and death of Nikola Tesla is one of the most fascinating yet tragic stories of scientific brilliance cutthroat business and shocking public relations stunts the American public may have been wowed by Edison's new direct current power stations but Tesla was less impressed he had a dream electricity could be transmitted across entire cities or even nations and he believed he knew how it could be done by using a different type of electric current Electrical experts know that the smaller the current sent down a cable the smaller the losses in it through resistance and so the longer the cable could be Tesla proposed using a method of transmitting electricity where the currents could be lowered without a fall in the amount of electrical power at the other end it was called alternating current alternating current is exactly there it's electric current that alternates between moving in one direction then the opposite direction very quickly as opposed to a direct current which moves only in one direction Tesla was interested in alternating current because like other electrical engineers in the late 1880s he realized that as you raise the voltage of any current that you transmit from point A to point B is going to be more efficient to have a higher voltage and since the amount of electric power in a cable is its voltage multiplied by its current increasing the voltage meant the current in the cables could be reduced and so losses due to resistance will be less however you don't want very high voltages on the order of say 20,000 volts coming into your home so you need to step down the current that is being transmitted over distance into your home and to do that you need a converter or a transformer alternating current allows you to use a transformer to make that switch from the high transmission voltage to the lower voltage that you're going to use at consumption [Music] perfecting the technology to transmit electricity hundreds of miles from where it was generated would mark a huge step towards the modern world and a wealthy industrial and tripping or was already developing the solution his name was George Westinghouse Westinghouse believed alternating currents was the future but it had a big drawback while it was fine for electric light unlike direct current there was no practical motor that could run on it and no one believed there ever would be apart from Nikola Tesla Tesla as an inventor liked to say that the first thing you need to do is not to build something but to imagine it to think it through to plant it and he had what modern-day psychologists would call an eidetic memory he could basically remember everything that he saw and then visualize it in three dimensions and they often say that the people would have this skill see it about an arm's length away out here and they see it in three dimensions in that space and all the indications are is this is Tesla had that ability this is a Tesla egg it's a replica of the one Tesla used to demonstrate his greatest breakthrough and one of the most important inventions of all time it showed how rotary movements can be produced directly from an alternating current crucially one that could be generated thousands of miles away this was something that had never been done before [Music] when Tesla was working on the alternating current motor he was thinking big and he was not just tinkering with one little component of the motor and saying gee if I can make that a little bit better it will work out he's actually thinking about an entire system that involves the generator the wires to the motor and the motor itself he's a complete maverick he's thinking outside the box he's doing things very differently than any of his fellow contemporary inventors Tesla's solution was ingenious he fed more than one alternating current into his motor and timed them so that they followed in sequence with each other the first alternating current energized a coil of wire inside the motor creating an electromagnetic field which attracted the motorists central moving part to it and then faded the second overlapping current fed the next coil dragging the movie part around further before it faded and the same for the third coil and the fourth the result was a revolving magnetic field strong enough to make the motor or in this case his egg spin Tesla designed an entire electrical system around this called polyphase transmission this meant a noisy and smelly power station generating lots of useful alternating current could now be situated away from populated areas and for the first time you can build large power stations wherever you want on the edge of town or a waterfall like Niagara and you can then distribute the power over long distances and serve all the people in a major city or or metropolitan center Tesla's breakthrough was the last piece of the jigsaw but he still had to convince the world that his solution was better than the direct current method championed by Edison Edison continued to roll out his direct current system building power stations across New York State the then Tesla met George Westinghouse the man who could make his dreams into a reality in July 1888 Westinghouse made an offer for Tesla's patents which has become part of the mystery and folklore surrounding the whole Nikola Tesla story and where it's difficult to separate fact from fiction Tesla was paid seventy five thousand dollars for his alternating current patents and offered two dollars 50 for every horsepower his motors would generate this should have guaranteed him vast wealth for the rest of his life but that isn't what happened it's clear to us now that at the time the a/c system was a much better method of transmitting electric power and you'd think that with Tesla's breakthroughs nothing could stand in the way of the success of AC / DC but one man still believed totally in his direct current inventions from the filaments of the bulbs to the switches sockets and generators and he wasn't about to waste millions of dollars on changing them Edinson the battle lines were drawn Westinghouse and Tesla went toe-to-toe with Edison for New York's lucrative lighting contracts two completely different systems battling it out for one ultimate prize the chance to light up America and then the world it will become known as the War of the currents both camps tried to undercut each other on cost but Edison believed his beloved direct currents was better than alternating current because it was safer touching an Edison cable with its low voltage was painful but relatively harmless whereas alternating current cables carried a much higher voltage and touching them could be deadly so what Aaron was trying to do was to again define his DC system right as the safe system it's better than Electric Street park lights it's better than gas and it's now better than high-voltage AC incandescent light it's the system that's safe you adopt the Edison system you can be sure it's gonna be safe Edison claimed that AC was a more dangerous type of current than DC and he highlighted every accident to Westinghouse his workmen and every fire caused by short circuits it was a potent message because in the 1880s many people were still terrified by electricity it could shock and even kill in an instant and the reasons why still weren't free understood for many the idea of piping this invisible killer into their homes was utterly ludicrous so the weapon used in the War of the currents was fear and a little-known electrical engineer Harold P Brown was about to take the fight against AC to a whole new level it was to prove one of the most extreme and negative publicity campaigns in history Brown had devised a unique and theatrical way of demonstrating the deadly power of AC and it was eager to share it with the world so on a warm summer's evening in July 1888 he gathered together 75 of the country's top electrical engineers and reporters to witness a spectacle they would never forget [Music] Brown's plan was extremely macabre he'd paid a team of street urchins to collect together stray dogs roaming Manhattan out on stage he addressed his audience I have asked you here gentlemen to witness the experimental application of electricity to a number of brutes his demonstration involved electrocuting the dogs with DC and AC power in an attempt to show that AC current killed them more quickly and it wasn't just dogs Brown went on to make public spectacles of killing a calf and even a horse and he moved from dogs to larger animals for a reason he wanted to show that the AC form of electricity was so dangerous it could kill any large mammal including humans [Music] Brown's animal experiments had persuaded American politicians the most humane method of executing condemned criminals should be with alternating current generated by westinghouse machines Edison's lawyers even suggested a new term to describe being electrocuted in this way to be Westinghouse and of precisely 6:30 to on the morning of the 6th of August 1890 a 45 year old man William Kemmler was strapped to a wooden chair and to soaking wet electrodes were carefully attached to him and as 26 officials and doctors looked on from an adjoining room Kemmler said goodbye to the prison chaplain and waited the execution of William Kemmler marked the lowest point in the war of the currents but it wouldn't quite mark the end because Nikola Tesla was about to do something that has never been seen before something so wondrous and daring that it would live on forever in the memories of those who saw [Music] [Applause] [Music] [Music] Tesla had been developing a method of generating very high-frequency alternating currents and on May 21st 1891 at a meeting of top electrical engineers he demonstrated it [Music] [Applause] in an almost magical display of awesome power and Wonder and without wearing any safety chain maille of last pins of thousands of volts produced by a Tesla coil passed across his body and through the end of a lab that he was holding Tesla's alternating current was at such a high frequency that it passed through his body without causing serious harm or even pain this demonstrations showed that it handled correctly alternating currents at extremely high voltages could be safe the War of the currents had been won by Westinghouse and Tesla in 1896 the new power station was completed at Niagara Falls using Westinghouse AC generators to produce Tesla's polyphase carriages finally huge amounts of power could be transmitted from the Falls to nearby Buffalo and then a few years later the Niagara plant was providing power to New York City itself and today almost all of the electricity generated in the world is done so using Tesla's system but Tesla story doesn't end in fame and fortune although he went on to make significant contributions to many other areas of science and invention to save George Westinghouse from ruin after a stock market crash he gave up his claim to the royalties from his polyphase inventions Nikola Tesla was a uniquely talented man and we owe him so much but it was also hugely complicated and sadly later in life he became more and more troubled he was fixated with the number three counting out loud as he walked and he developed strange phobias with germs and with women wearing pearl jewelry in many ways his brilliant mind simply spun out of control as Tesla's life unraveled he withdrew from people and found emotional comfort elsewhere he became obsessed with pigeons and was regularly seen feeding them here in Bryant Park in the center of Manhattan he even fell in love with one particularly unusual white bird and when it died he was left heartbroken as an old man Tesla was left almost bankrupt and alone living as a semi recluse in this hotel his last years were spent here in room three three to seven of The New Yorker Hotel sad confused destitute Edison went on to become an American hero and his company would form part of General Electric even today one of the world's biggest multinational corporations in January 1943 the story of Nikola Tesla was coming to an end but looking out across the Manhattan skyline for the very last time he saw a sky lit up with twinkling lights and a million lives transformed by his genius [Music] the ability to generate and transmit electricity and the invention of machines to use it have changed our world in ways we couldn't possibly have imagined we can now generates billions of watts of electricity every second every hour every day and whether we do it using coal gas or nuclear fission power stations all rely on the principles discovered and developed by Michael Faraday Nikola Tesla and all the other early electrical engineers from an amazing age of invention we now take electricity for granted and have forgotten how magical and mysterious a force it once was but there's something we should never forget today without it the modern world would collapse around us and our lives would be very very different [Music] in the next episode we tell of the electrical revelations that led to a revolution in our understanding of this amazing force [Music] on the 14th of august 1894 an excited crowd gathered outside Oxford's Natural History Museum this huge Gothic building was hosting the annual meeting of the British Association for the Advancement of science over two thousand tickets had been sold in advance and the museum was already packed waiting for the next talk to be given by Professor Oliver Lodge his name might not be familiar to us now but his discoveries should have made him as famous as some of the other great Electrical pioneers of history people like Benjamin Franklin Alessandro Volta or even the great Michael Faraday quite unwittingly he would set in motion a series of events that would revolutionize the Victorian world of brass and telegraph wire this lecture would mark the birth of the modern electrical world a world dominated by silicon and mass wireless communication [Music] in this program we discover how electricity connected the world together through broadcasting computer networks and how we finally learned to unravel and exploit electricity at an atomic level [Music] after centuries of man's experiments with electricity a new age of real understanding was now dawning [Music] these tubes are not plugged into any power source but they still light up its electricity's invisible effect an effect not just confined to the wires it flows through in the middle of the 19th century a great theory was proposed to explain how this could be the theory says that surrounding any electric charge and there's a lot of electricity flowing above my head is a force field these fluorescent tubes are lit purely because they're under the influence of the force field from the power cables above the theory that a flow of electricity could in some way create an invisible force field was originally proposed by Michael Faraday but it would take a brilliant young Scotsman called James Clark Maxwell who would prove Faraday correct and not through experimentation but through mathematics [Music] this was all a far cry from the typical 19th century way of understanding how the world works which was essentially to see it as a physical machine [Applause] [Music] before Maxwell scientists had often built strange machines or devised wondrous experiments to create and measure electricity but Maxwell was different he was interested in the numbers and his new theory not only revealed electricity's invisible force field but how it could be manipulated it would prove to be one of the most important scientific discoveries of all time Maxwell was a mathematician and a great one and he saw electricity and magnetism in an entirely new way he expressed it all in terms of a very compact mathematical equations and the most important thing is that in Maxwell's equations is an understanding of electricity and magnetism as something linked and as something that can occur in waves [Music] Maxwell's calculations showed how these fields could be disturbed rather like touching the surface of water with your finger changing the direction of the electric current would create a ripple or wave through these electric and magnetic fields and constantly changing the direction of the flow of the currents forwards and backwards like an alternating current would produce a whole series of waves waves that would carry energy Maxwell's maths was telling him that changing electric currents would be constantly sending out great waves of energy into their surroundings waves that would carry on forever unless something absorb them Maxwell's maths was so advanced and complicated that only a handful of people understood it at the time and although his work was still only a theory it inspired a young German physicist called Heinrich Hertz Hertz decided to dedicate himself to designing an experiment to prove that Maxwell's waves really existed and here it is this is Hertz his original apparatus and his beauty is in its sheer simplicity he generates an alternating current that runs along these metal rods with a spark that jumps across the gap between these two spheres now if Maxwell was right then this alternating current should generate an invisible electromagnetic wave that spreads out into the surroundings if you place a wire in the path of that wave then at the wire there should be a changing electromagnetic field which should induce an electric current in the wire so what Hertz did was build this ring of wire his receiver that he could carry around in different positions in the room to see if he could detect the presence of the wave and the way he did that was leave a very tiny gap in the wire across which a spark would jump if a current runs through the ring now because the current is so weak that spark is very very faint and Hertz spent pretty much most of 1887 in a darkened room staring intensely through a lens to see if he could detect the presence of this faint spark but Hertz wasn't alone in trying to create Maxwell's waves back in England a young physics professor called Oliver Lodge had been fascinated by the topic for years but hadn't had the time to design any experiments to try to discover them then one day in early 1888 while setting up an experiment on lightning protection he noticed something unusual lodged noticed that when he set up his equipment and sent an alternating current around the wires he could see glowing patches between the wires and with applets working he saw these glowing patches formed a pattern the blue glow an electrical sparks occurred in distinct patches evenly spaced along the wires he realized they were the peaks and troughs of a wave an invisible electromagnetic wave Lodge had proved that Maxwell was right finally by accident Lodge had created Maxwell's electromagnetic waves around the wires the big question had been answered [Music] filled with excitement at his discovery large prepared to announce it to the world that summers and your scientific meeting run by the British Association before it though he decided to go on holiday his timing couldn't have been worse because back in Germany and at exactly the same time Heinrich Hertz was also testing Maxwell's theories eventually Hertz found what he was looking for a minut spark and as he carried his receiver around different positions in the room he was able to map out the shape of the waves being produced by his apparatus and he checked each of Maxwell's calculations carefully and tested them experimentally it was a tour de force of experimental science back in Britain as the crowds gathered for the British Association meeting Oliver Lodge returned from holiday relaxed and full of anticipation [Music] this Lodge thought would be his moment of triumph when he could announce his discovery of Maxwell's waves his great friend the mathematician Fitzgerald was due to give the opening address in the meeting but in it he proclaimed that Heinrich Hertz had just published astounding results he had detected Maxwell's waves traveling through space we have snatched the Thunderbolt from Jove himself and enslaved the all-pervading ether he announced well I can only imagine how Lodge must have felt having his Thunder stolen professor Oliver Lodge had lost his moment of triumph pipped at the post by Heinrich Hertz heard a spectacular demonstration of electromagnetic waves what we now call radio waves even though he didn't know it at the time is going to lead to a whole revolution in communications over the next century [Music] Maxwell's theory had shown how electric charges could create a force field around them and that waves could spread through these fields like ripples on a pond and Hertz had built a device that could actually create and detect the waves as they passed through the air but almost immediately there would be another revelation in our understanding of electricity a revelation that would once again involve professor Oliver Lodge and once again his Thunder would be stolen the story stands in Oxford in the summer of 1894 Hertz had died suddenly earlier that year and so large prepared a memorial lecture with a demonstration that would bring the idea of waves to a wider audience Lodge had worked on his lecture he'd researched better ways of detecting the waves and he'd borrowed new apparatus from friends he'd made some significant advances in the technology designed to detect the waves this bit of apparatus generates an alternating current and a spark across this gap the alternating current sends out an electromagnetic wave just as Maxwell predicted that is picked up by the receiver it sets off a very weak electric current through these two antennae now this is what Hertz had done larges improvements on this was to set up this tube full of iron filings the weak electric current passes through the filings forcing them to clump together and when they do they close a second electric circuit and set off the Bell so if I push the button on this end it sets off the bell at the receiver and it's doing that with no connections between the two it's like magic you could imagine a packed house lots of people in the audience and what they suddenly see is as if by magic a bell ringing is quite incredible it might not have been the most dramatic demonstration the audience had ever seen but it certainly still created a sensation among the crowd logis apparatus laid out like this no longer looked like a scientific experiment in fact it looked remarkably like those telegraph machines that had revolutionized communication but without those long cables stretching between the sending and receiving stations to the more worldly and savvy members of the audience this was clearly more than showing the maestro Maxwell was right this was a revolutionary new form of communication Lodge publishes lecture notes on how electromagnetic waves could be sent and received using his new improvements all around the world inventors amateur enthusiasts and scientists read lodges reports with excitement and began experimenting with Hertzian waves [Music] to utterly different characters were to be inspired by it both would bring improvements to the wireless Telegraph and both will be remembered for their contribution to science and far more than Oliver Lodge the first was ghoulia mo Marconi Marconi was a very intelligent astute and a very charming individual he definitely had the Italian Irish charm he could apply this to almost anyone from sort of young ladies to world-renowned scientists Marconi was no scientist but he read all he could of other people's work in order to put together his own wireless Telegraph system and it's possible that because he was brought up in Bologna and it was fairly close to the Italian coast that he saw the potential of wireless communications in relation to maritime usage fairly early on then aged only 22 he came to London with his Irish mother to market it the other person inspired by lodges lecture was a teacher at the Presidency College in Calcutta called Jagadish Chandra Bose despite degrees from London and Cambridge the appointment of an Indian as a scientist in Calcutta have been a battle against racial prejudice Indians it was said didn't have the requisite temperament for exact science well Bose was determined to prove this wrong and here in the archives we can see just how fast he's set to work this is a report of the 66th meeting of the British Association and Liverpool September 1896 and here is Bose the first Indian ever to present at the Association meeting talking about his work and demonstrating his apparatus he built and improved on the detector that Lodge described because in the hot sticky Indian climates he'd found that the metal filings inside the tube that that Lodge used to do to detect the waves became rusty and stuck together so Bose had to build a more practical detector using a coiled wire instead his work was described as a sensation the detector was extremely reliable and could work on board ships so had great potential for the vast British naval fleet Britain was the center of a vast telecommunications network which stretched almost around the world which was used to support an equally vast maritime network of merchant and naval vessels which were used to support the British Empire but Bose a pure scientist wasn't interested in the commercial potential of wireless signals unlike Marconi this was a sort of a new cutting-edge field but Marconi wasn't a trained scientist so did come things in a fairly different way which is made may have been why he progressed so quickly in the first place and he was very good at forming connections with the people that he needed to form connections with to enable his work to be done Marconi used his connections to go straight to the only place that had the resources to help him the British post office was a hugely powerful institution when Marconi first arrived in London in 1896 these buildings were newly completed and already moving with business from the Empire's postal and telegraph eServices Marconi had brought his Telegraph system with him from Italy claiming it could send wireless signals over unheard-of distances and the post office engineer in chief William priest immediately saw the technology's potential so priests offered Marconi the great financial and engineering resources of the post office and they started work up on the roof the old headquarters of the post office were right there and between this roof and that one Marconi and the post office engineers would practice sending and receiving electromagnetic waves the engineers helped him improve his apparatus and then priests and Marconi together demonstrated it to influential people in government and the Navy what priests didn't realize was that even as he was proudly announcing Marconi's successful partnership with the post office Marconi who was making plans behind the scenes he'd applied for a British patent on the whole field of wireless telegraphy and was planning on setting up his own company when the patent was granted all hell broke loose in the scientific community that patent was itself revolutionary you see patents could only be taken out of things that weren't public knowledge but Marconi famously had hidden his equipment in a secret box and here it is when his patent was finally granted Marconi ceremoniously opened the box everyone was keen to see what inventions lay within batteries forming a circuit iron filings in the tube to complete the circuit to ring the bell on top nothing they hadn't seen before and yet Marconi had patented the lot the reason why Marconi is famous it's not because of that invention he doesn't invent radio right but he improves it and turns it into a system Lodge doesn't do that and that's why remember Marconi and that's why we don't remember Lodge [Music] the scientific world was up in arms here was this young man who knew very little about the science behind his equipment about to make his fortune from their work even his great supporter priests was disappointed and hurt when he found out that Marconi was about to go it alone and set up his own company Lodge and other scientists began a frenzy of patenting every tiny detail and improvement they made to their equipment this new atmosphere shocked Bose when he returned to Britain Bose wrote home to India in disgust of what he found in England money money money all the time what a devouring greed I wish you could see the craze for money of the people here his disillusionment with the changes he saw in the country he revered for its scientific integrity and an excellence is palpable eventually though it was his friends who convinced Bose to take out his one and only patent on his discovery of a new kind of detector for waves it was this discovery that would lead to perhaps an even greater revolution for the world he had discovered the power of crystals this were places older techniques using iron filings which are messy and difficult and don't work well and here's a whole new way of detecting radio waves and it's one that's going to be at the center of a radio industry BOCES discovery was simple but it would truly shape the modern world when some crystals are touched with metal to test their electrical conductivity they can show rather odd and very behavior take this crystal for example if I can touch us in exactly the right spot with the tip of this metal wire and then hook it up to a battery it gives quite a significant current but if I switch around my connections to the battery and try and pass the current through in the opposite direction it's a lot less it's not a full conductor of electricity it's a semiconductor and it found its first use in detecting electromagnetic waves when boasts used a crystal like this in his circuits instead of the tuber filings he found it was a much more efficient and effective detector of electromagnetic waves it was this strange property of the junction between the wire known as the cat's whisker and the crystal which allowed current to pass much more easily in one direction than the other that meant it could be used to extract a signal from electromagnetic waves at the time no one had any idea why certain crystals acted in this way but two scientists and engineers the strange behavior had a profound an almost miraculous practical effect with crystals as detectors now it was possible to broadcast and detect the actual sound of a human voice or music in his Oxford lecture in 1894 Oliver Lodge had opened a Pandora's box as an academic he'd failed to foresee that the scientific discoveries he'd been such a part of had such commercial potential the one Paton he had managed to secure the crucial means of tuning a receiver to a particular radio signal was bought off him by Marconi's powerful company perhaps the worst indignation for lodge though would come in 1909 when Marconi was awarded the Nobel Prize in Physics for wireless communication it's difficult to imagine a bigger snub to the physicist who's so narrowly missed out to Hertz in the discovery of radio waves and who'd then go on to show the world how they could be sent and received but despite the snub Lodge remained magnanimous using the new broadcasting technology that resulted from his work to give credit to others as this rare film of him shows pets made a great advance he discovered how to produce and detect waves in space thus bringing the ether into practical use harnessing x' harnessing is for the transmission of intelligence in a way which has subsequently been elaborated by a number of people [Music] today we can hardly imagine a world without broadcasting to imagine a time when radio waves hadn't even been dreamt of engineers continued to refine and perfect our ability to transmit and receive electromagnetic waves but their initial discovery was ultimately a triumph of pure science from Maxwell through Hertz to launch but still the very nature of electricity itself remained unexplained what created those electrical charges and currents in the first place although scientists were learning to exploit electricity they still didn't know what it actually was but this question was being answered with experiments looking into how electricity flowed through different materials back in the 1850s one of Germany's great experimentalists and a talented glassblower Heinrich Geissler created these beautiful show pieces [Music] Geisler pumped most of the air out of his intricate glass tubes and then had small amounts of other gases pumped in he then passed an electrical current through them they glowed with stunning colors and the current flowing through the gas seen tangible although they were designed purely for entertainment over the next 50 years scientists or guys 'less tubes has a chance to study how electricity flowed efforts were made to pump more and more air out of the tubes could the electric current pass through nothingness through the vacuum this is a very rare flick book film of the British scientist who created a vacuum good enough to answer that question his name was William Crookes crooks created tubes like this he pumped out as much of the air as he could so that it was as close to a vacuum as he could make it then when he passed an electric current through the tube he noticed a bright glow on the far end a beam seemed to be shining through the tube and hitting the glass at the other end it seemed at last we could see electricity the beam became known as a cathode ray and this tube was the forerunner of the cathode ray tube that was used in television sets for decades physicist JJ Thompson discovered that these beams were made up of tiny negatively charged particles and because they were carriers of electricity they became known as electrons because the electrons only moved in one direction from the heated metal plate through the positively charged plate at the other end they behaved in exactly the same way as BOCES semiconductor crystals but whereas BOCES crystals were naturally temperamental you had to find the right spot for them to work these tubes could be manufactured consistently they became known as valves and they soon replaced crystals in radio sets everywhere [Music] these discoveries would lead to an explosion of new technology early 20th century electronics is all about what you can do with valves so the radio industry is built and valves early television is built and valves early computers are built with valves these are the things that you build the electronic world with having discovered how to manipulate electrons flowing through a vacuum scientists were now keen to understand how they could flow through other materials but that meant understanding the things that made up materials atoms [Music] it was in the early years of the 20th century that we finally got a handle on exactly what atoms were made up of and how they behaved and so what electricity actually was on the atomic scale at the University of Manchester Ernest Rutherford's team were studying the inner structure of the atom and producing a picture to describe what an atom looked like this revelation would finally help explain some of the more puzzling features of electricity by 1913 the picture of the atom was one in which you had a positively charged nucleus in the middle surrounded by negatively charged orbiting electrons in patterns called shells each of these shells corresponding to an electron with a particular energy now given an energy boost an electron could jump from an inner shell to an outer one and the energy had to be just right if it wasn't enough the electron wouldn't make the transition and this boost was often temporary because the electron would then drop back down again to its original shell as it did this it had to give off its excess energy by spitting out a photon and the energy of each photon depended on its wavelength or as we would perceive it it's color understanding the structure of atoms could now also explain nature's great electrical light shows just like guys 'less tubes the type of gas the electricity passes through defines its color lightning has a blue tinge because of the nitrogen in our atmosphere higher in the atmosphere the gases are different and so is the color of the photons they produce creating the spectacular Aurora's understanding atoms how they fit together in materials and how their electrons behave was the final key to understanding the fundamental nature of electricity this is a Wimshurst machine and it's used to generate electric charge electrons are rubbed off these discs and start a flow of electricity through the metal arms of the machine now metals conducts electricity because the electrons are very weakly bound inside their atoms and so can slosh about and be used to flow as electricity insulators on the other hand don't conduct electricity because the electrons are very tightly bound inside the atoms and are not free to move about the flow of electrons and hence electricity through materials was now understood conductors and insulators could be explained what was more difficult to understand was the strange properties of semiconductors our modern electronic world is built upon semiconductors and would grind to a halt without them Jagadish Chandra Bose may have stumbled upon their properties back in the 1890s but no one could have foreseen just how important they were to become but with the outbreak of the Second World War things were about to change [Music] here in Oxford this newly-built physics laboratory was immediately handed over to the war research effort the researchers here were tasked with improving the British radar system Rader was a technology that used electromagnetic waves to detect enemy bombers and as its accuracy improved it became clear that valves just weren't up to the job so the team had to turn to old technology incentive valves they used semiconductor crystals now they didn't use the same sort of crystals that Bost had developed instead they use silicon this device is the silicon crystal receiver as a tiny tungsten wire coiled down and touching the surface of a little silicon crystal it's incredible how important a device it was it was the first time silicon had really been exploited as a semiconductor but for it to work it needed to be very pure and both sides in the war put a lot of resources into purifying it in fact the British had better silicon devices so they must have had some cause of silicon already at a time which we were just started with you know and being in Berlin the British had better silicon semiconductors because they had help from laboratories in the u.s. in particular the famous Bell Labs and it wasn't long before physicists realized that if semiconductors could replace valves in radar perhaps they could replace valves in other devices too like amplifiers the simple vacuum tube with its one-way stream of electrons had been modified to produce a new device by placing a metal grille in the path of the electrons and applying a tiny voltage to it a dramatic change in the strength of the beam could be produced these valves worked as amplifiers turning a very weak electrical signal into a much stronger one an amplifier is something and once it's really simple you just take a small current you turn it into a large account but in other ways it changes the world because when you can amplify a signal you can send it anywhere in the world as soon as the war was over German experts Herbert matarae and his colleague Heinrich Volker started to build a semiconductor device that could be used as an electrical amplifier and here is that first working model that matter a embel car made if you look inside you can see the tiny crystal and the wires that make contact with it if you pass a small current through one of the wires this allows a much larger current to flow through the other one so it was acting as a signal amplifier these tiny devices could replace big expensive valves in long-distance telephone networks radios and other equipments where a faint signal needed boosting matarae immediately realized what he'd created but his bosses were initially not interested not that is until a paper appeared in a journal announcing at Bell Labs discovery a research team there had stumbled across the same effect and now they were announcing their invention to the world they called it the transistor they had December 1947 and we had at the beginning 48 but just just just life you know they had a little bit earlier the effect but funnily enough the transistors were just no good although the European device was more reliable than bell labs more experimental model neither quite fulfilled their promise they worked that were just too delicate so the search was on for a more robust way to amplify electrical signals and the breakthrough came by accident in Bell Labs silicon crystal expert Russell all noticed that one of his silicon ingots had a really bizarre property it seemed to be able to generate its own voltage and when you try to measure this by hooking it up to an oscilloscope he noticed that the voltage changed all the time the amount of voltage generated seemed to depend on how much light there was in the room so by casting a shadow over the crystal he saw the voltage dropped more light meant the voltage went up what's more when he turned a fan on between the lamp and the crystal the voltage started to oscillate with the same frequency that the blades of the fan were casting shadows over the crystal [Music] one of olds colleagues immediately realized that the ingot had a crack in it that formed a natural Junction and this tiny natural Junction in an otherwise solid block was acting just like the much more delicate junction between the end of a wire and a crystal that boasts had discovered except here it was sensitive to light the ingots had cracked because either side contains slightly different amounts of impurities one side has slightly more of the element phosphorus while the other has slightly more of a different impurity boron and electrons seem to be able to move across from the phosphorus side to the boron side but not vice-versa photons of light shining down onto the crystal were knocking electrons out of the atoms but it was the impurity atoms were driving this flow phosphorus has an electron that is going spare and boron is keen to accept another so electrons tended to flow from the phosphorus side to the boron side and crucially only flowed one way across the junction [Music] the head of the semiconductor team William Shockley saw the potential of this one-way junction with inner crystal but how would it be possible to create a crystal with two junctions in it that could be used as an amplifier another researcher at Bell Labs called Gordon teal had been working on a technique that would allow just that [Music] he discovered a special way to grow single crystals of the semiconductor germanium in this research institute they grow semiconductor crystals in the same way that teal did back in Bell Labs only here they grow them much much bigger at the bottom of this VAT is a container with glowing hot molten germanium just as pure as you can get it inside it are a few atoms of whatever impurity is required to alter is conductive properties now the rotating arm above has a seed crystal at the bottom that has been dipped into the liquid and will be slowly raised up again as the germanium cools and hardens it forms a long crystal like an icicle below the seed the whole length is one single beautiful germanium crystal [Music] Teil worked out that as the crystal is growing other impurities can be added to the vats and mixed in this gives us a single crystal with thin layers of different impurities creating junctions within the crystal [Applause] [Music] this crystal with two junctions in it was Shockley's dream applying a small current through the very thin middle section allows a much larger current to flow through the whole triple sandwich from a single crystal like this hundreds of tiny solid blocks could be cut each containing the two junctions that would allow the movement of electrons through them to be precisely controlled these tiny and reliable devices could be used in all sorts of electrical equipment you cannot have the electronic equipment that we have without tiny components and you get a weird effect that it is smaller they get the more reliable they get it's a win-win situation the Bell Labs team were awarded the Nobel Prize for their world-changing invention while a European team were forgotten William Shockley left Bell Labs and in 1955 set up his own semiconductor laboratory in rural California recruiting the country's best physics graduates but the celebratory mood didn't last long because Shockley was almost impossible to work for people left his company because they just disliked the way he treated them so the fact that Shockley was that sees such a gate is why you have Silicon Valley it starts that whole process of spin-off and growth and new companies and it all starts off with Shockley being such a shocking human being [Music] the new companies were in competition with each other to come up with the latest semiconductor devices they may transistors so small that huge numbers of them could be incorporated into an electrical circuit printed on a single slice of semiconductor crystal these tiny and reliable chips could be used in all sorts of electrical equipment most famously in computers a new age had dawned today microchips are everywhere they've transformed almost every aspect of modern life from communication to transport and entertainment but perhaps just as importantly our computers have become so powerful they're helping us to understand the universe in all its complexity a single microchip like this one today can contain around 4 billion transistors it's incredible how far technology has come in 60 years it's easy to think that with the great leaps we've made in understanding and exploiting electricity there's little left to learn about it but we'd be wrong for instance making the circuits smaller and smaller meant that a particular feature of electricity that had been known about for over a century was becoming more and more problematic resistance a computer chip has to be continuously cooled if you take away the fan this is what happens while that's shooting up 100 120 130 degrees [Music] 200 degrees and it cut out that just took a few seconds and the chip is well and truly cooked you see as the electrons flow through the chip they're not just traveling around unimpeded they're bumping into the atoms of silicon and the energy being lost by these electrons is producing Heat now sometimes this was useful inventors made electric heaters and ovens and whenever they got something to glow white-hot well that's a light bulb but resistance in electronic apparatus and in power lines is the major waste of energy and a huge problem it's thought that resistance wastes up to 20 percent of all the electricity we generate it's one of the greatest problems of modern times and the search is on for a way to solve the problem of resistance what we think of as temperature is really a measure of how much the atoms of the material are vibrating and if the atoms are vibrating then electrons flowing through are more likely to bump into them so in general the hotter the material the higher its electrical resistance and the cooler it is the lower the resistance but what happens if you call something right down close to absolute zero minus 273 degrees Celsius well an absolute zero there's no heat at all and so the atoms aren't moving at all what happens then to the flow of electricity the flow of electrons using a special device called a cryostat that can keep things close to absolute zero we can find out inside this cryostat in this coil is mercury the famous liquid metal and it forms part of an electric circuit now this equipment here measures the resistance in the mercury but look what happens as I lower the mercury into the coldest part of the cryostat there it is the resistance has dropped to absolutely nothing mercury like many substances we now know have this property is called becoming superconducting which means there have no resistance at all to the flow of electricity but these materials only work when they're very very cold if we could use a superconducting material in our power cables and in our electronic apparatus we'd avoid using so much of our precious electrical energy through resistance the problem of course is that superconductors had to be kept at extremely low temperatures then in 1986 a breakthrough was made in a small laboratory near Zurich Switzerland IBM physicists recently discovered their superconductivity and the class of materials that is being called one of the most important scientific breakthroughs in many decades this is a block of the same material made by the researchers in Switzerland it doesn't look very remarkable but if you cool it down with liquid nitrogen something special happens it becomes a superconductor and because electricity and magnetism are so tightly linked that gives it equally extraordinary magnetic properties this magnet is suspended levitating above the superconductor the exciting thing is that although cold this material is way above absolute zero [Music] these magnetic fields are so strong that not only can they support the weight of this magnet but they should also support my weight I'm about to be levitated it's very very strange sensation when this material was first discovered in 1986 it created a revolution not only had no one considered that it might be superconducting but it was doing so at a temperature much warmer than anyone has thought possible we are tantalisingly close to getting room-temperature superconductors we're not there yet but one day a new material will be found and when we put that into our electronic equipment we could build a cheaper better more sustainable world today materials have been produced that exhibit this phenomenon at the sort of temperatures you get in your freezer but these new superconductors can't be fully explained by the theoreticians so without a complete understanding experimentalists are often guided as much by luck as they are by a proper scientific understanding recently a laboratory in Japan held a party in which they ended up dosing their superconductors with a range of alcoholic beverages unexpectedly they found that red wine improves the performance of the superconductors [Music] Electrical research now has the potential once again to revolutionize our world if room-temperature superconductors can be found [Music] our addiction electricity's power is only increasing and when we fully understand how to exploit superconductors a new electrical world will be upon us it's going to lead to one of the most exciting periods of human discovery and invention a brand new set of tools techniques and technologies to once again transform the world [Music] electricity has changed our world only a few hundred years ago it was seen as a mysterious and magical wonder then elect out of the laboratory with a series of strange and wondrous experiments eventually being captured and put to use it revolutionized communication first through cables and then as waves through electricity's far-reaching fields it powers and lights the modern world today we can hardly imagine life without electricity it defines our era and will be utterly lost without it and yet it still offers us more we stand once again at the beginning of a new age of discovery a new revolution but above all else there's one thing that all those who deal in the science of electricity know it's story is not over yet [Music] [Music]

Channel: Trev M

Views: 6,593,715

Rating: 4.5529618 out of 5

Keywords: Jim Al-Khalili (Academic), Shock And Awe: The Story Of Electricity (TV Program), Horizon (Award-Winning Work), Physics (Field Of Study), electricity, magnetism, electromagnetism, Documentary (TV Genre), Benjamin Franklin, Henry Cavendish, Galvani, Volta, Oersted, Faraday, Morse, Thomas Edison, Nikola Tesla, Tesla, James Clerk Maxwell, Heinrich Hertz, BBC Horizon, Shock and Awe

Id: Gtp51eZkwoI

Length: 174min 55sec (10495 seconds)

Published: Tue May 26 2015

Reddit Comments

[u/opiumADDICT]

Amazing documentary on the history of electricity, Nothing better.

[u/gill_outean]

I watch his "Everything & Nothing" on 200ug and felt like god cummed in my brain.